Apparatus for handling mixed concrete



E. D. ALESSIO APPARATUS FOR HANDLING MIXED CONCRETE Sept. 18, 1951 2Sheets-Sheet 1 Filed July 15, 1950 I N V EN TOR.

[way To 3/41. E53 IO Sept. 18, 1951 E. D. ALESSIO APPARATUS FOR HANDLINGMIXED CONCRETE Filed July 15 1950 2 Sheets-Sheet 2 INVENTOR fkzves 70D4668/0 7 ATTORNEY Patented Sept. 18, 1951 OFFICE APPARATUS FOR HANDLINGMIXED CONCRETE Ernesto n. lllesslo; Akron, Ohio Application July 13,1950, Serial No. 173,556

3 Claims. flci. 259178) I This invention relates to the handling ofmixed concrete. More particularly, it relates to an im-' proved methodfor maintaining the concrete in a fluid, pourable condition whiletransportingit to a construction site where it is to be poured. Theinvention includes a preferred apparatus for carrying out the method. a

Concrete for ordinary construction purposes .is

commonly prepared at a centrally located plant wherethe properproportions of Portland cement, water, and aggregate are carefullymeasured for is equipped with means to agitate the concrete. in transitto prevent it from setting before it is poured. Some vehicles areequipped with means for mixing the concrete as well as agitating themixed material. the vehicle is adapted to be operated at two differentspeeds, one for mixing and one for agitating the mixed material.

The usual vehicular equipment includes a horizontal cylindrical tank (ortank of other shape) provided with means for rotating it on a horizon-.

tal axis. The rotation of the tank mixesthe .concrete or slowly agitatesit after mixing. Such tumbling or other violent agitation is harmful to.the concrete because it strips the cement paste from the aggregate, andafter setting, concrete which has been thus violently agitated during'transportation to the construction site has a lower strength than if ithad'not been agitated Stirring is not as harmful as tumbling or thelike, and does little or no damage to a thoroughly.

mixed concrete.

Concrete which has been tumbled in transit solidifies very rapidly. Thismakes it difficult to handle. Concrete which has been merely stirred intransit does not solidify so rapidly, other conditions being comparable.It is therefore more easily handled. 1

Heat is liberated as the cement in the concrete is hydrated and as theconcrete solidifies.

heating has a tendency to vaporize and drive off a portion of the waternot yet combined with the cement. This loss may be compensated for inthe water-cement ratio when the mix is prepared, but'a certain amount ofheat is generated by the tumbling, due to the striking of the aggregatesagainst one another, etc., and this cannot be accurately predicted. As aconsequence, it is Often the agitatingmeans on.

impossible to calculate the amount of water which will be lost duringtumbling, and there is no way of accurately compensating for it. This initself is a serious objection to the ordinary method of agitating theconcrete while transporting it.

According to this invention the concrete is mixed at a central plantwhere the necessary water is mixed with the other ingredients. Thevarious ingredients are thoroughly mixed. The mixed concrete is thentransferred to a tank or other container on a suitable vehicle, such asa truck. Means is provided for slowly stirring the concrete while itisbeing transported, without tumbling it- The stirrer merely displaces thevarious particles of aggregate in the fluid or plastic mass of theconcrete mix from time to time so as to prevent the mass fromsolidifying. The preferred stirrer reciprocates slowly back and forththrough the plastic mass. This stirring action continues from the timethe vehicle is loaded until the concrete is ready to be poured. It hasno appreciable efiect upon the temperature of the concrete or the amountof water vaporized from it.

The preferred stirrer of this invention may be readily installed on anyvehicle equipped with a truck body suitable for hauling liquid. It isreadily installed on any conventional dump truck. It includes one ormore horizontally disposed stirring bars which are immersed in theconcrete and are reciprocated back and forth through the concrete bypower means which is preferably driven by the motor or the truck.Preferably, the forwardand rear edges of the stirring bars arerelatively sharp and the top and bottom surfaces of these bars slopegradually away from both edges. As the bars are moved through theconcrete they tend to displace some of the particles of the mix upwardlymomentarily, and the particles then sink back of their own accord.v

This prevents the aggregate from settling toward the bottom of the mix.The stirring is preferably effected with minimum change in thecomposition of the material on the surface of the concrete. The movementof the particles of the aggregate is slight, but sufficient to preventthe batch from solidifying.

The improved method and the preferred apparatus will be furtherdescribed with reference to the drawings, in which- Fig. l is a sideelevation of a dump truck body with the preferred apparatus installedthereon; Figs. 2 and 3 are cross-sectional detail views of element forthe equipment shown includes the.

three bars l, 2 and 3. These stirring bars are bottom. As shown in Fig.5, the crank 30 is located at the center of the shaft and the shaft issupported below the bottom of the body by suitable bearings 35.

The ends 31 of the shaft project outwardly a short distance at each sideof the body and a flat bar 38 is rigidly fastened around each end 3! bya key 4|]. Each bar 38 extends upwardly from the .shaft close to itsrespective .sid ,of the body and its upper end is pivotally connected bya rivet 42 to the end of another flat bar 33. The

rivet 42, as shown in Fig. 3, extends loosely disposed horizontally withone spaced vertically above the other.

They are supported at their ends by the vertical uprights 4, 4.Reinforcing ring bars, as shown in Fig. 2. These rods are preferablyformed with a diamond-shaped cross section but they may be round.

Each of the upper stirring bars has a diamondshaped .cross section, asshown in Fig. 4. The forward edge 1 and the rear edge, 8 of these barsare sharp, and the top and bottom surfaces 9 taper backwardly from eachedge with a fairly low slope. The taper of each sloping portion of thetop surface is preferably less than thirty degrees. The lowest stirringbar 3 has a triangular cross section. 'Its forward and rear edges aresharp and its top surface is tapered similarly to the bars I and 2, butthe bottom of bar 3 is flat.

The stirring element fits inside the body II of the truck so that thestirring bars extend laterally across thebody substantially parallel tothe bottom of the truck. The uprights 4, 4 are located close to thesides of the truck and the lowest stirring bar 3 is located just abovethe bottom of the body. The upper ends of the uprights 4 pro-' jectabove the top of the sides of the body somewhat and a bar I2 is weldedacross the upper ends of these uprights. The portions l3 at each end ofthe bar l2 project out across the top' edge of the sides of the body anda flat plate is welded to each end l3. The plates I5 are relativelywide, as shown in Fig. l, and they extend vertically downward parallelto the uprights'd but of the sides of the are along the outside surfacetruck.

A pair of rollers I8 is mounted on the inside surface of each plate I 5near the corner 19- formed where the plate I5 is welded to the end l3 ofthe bar I2. The rollers t8 extend inwardly toward the sides of the body.adapted to roll in a track 29 located along the top of each side of thebody. Each track 29 is preferably a length of channel iron which restson the outwardly turned flange 22 along the top of the sides of the bodyand extends from the front to the rear of the body. The channelsarepositioned with their legs projecting horizontally outwardly to receivethe rollers it which roll back and forth on the legs when the stirringelement is moved through the concrete in the body.

The reciprocating action may be obtained by a variety. of differentstructures. Preferably a fluid 7 pressure cylinder 23 is employed tosuplly. the

power required to reciprocate the stirring element. The cylinder 23 isoperated from the hydraulic system which normally operates cylinder 24which raises and lowers the body. Cylinder 23 is pivotally mounted at 28under the bottom of the body. The outer end of its piston rod 29 isfastened to a crank 33 which is rigidly connected to and projectsdownwardly from a shaft 32 which extends laterally across the body underits Each pair isthrough the upper end of bar 38 and the abutting end oflbar 13, and is held in place by cotter pin 1:5. 'Bar 43 slopesdownwardly toward the rear of. the body and its lower end is pivotallyengaged with the downwardly extending plate l5 by a rivet l8 whioh-extends through bar 43 and through a hole .49 (Fig. 2) in plate [5. Therivet is removably fastened in place by cotter pin 50.

Fig. 1 showsthe relative position of the bars 38 and '43 in solid lineswhen the stirring element is at the rear .of the .body next .to thetailgate. The broken lines indicate therelat'ive position of these samebars when the .st'irring element :is shifted toa position near the frontend'of the body. To move the stirring. element from the rear of the bodyto the forward position shown, fluid is introduced into the cylinder23soth at its piston rod 29 is retracted into the cylinder. (See Fig. 6;)the crank toward the rear of the truck thereby rotating the shaft 32 toswing the bars '38 on each end of the shaft forwardly toward the cab.The movement of the bars '38 shifts the bars 43 forward so that thestirring element'is pulled toward the front of the body." Rollers 1-18rollv along the track 20 as the stirrirrg element isv When the stirrerreaches the front of the body.

the valve apparatus 55 operates to reverse the flow of fluid -into thecylinder '23 so that the piston 29 is forced out of the cylinder andcrank 30 is swung forwardly toward the cab. This rotation of shaft 32swings the bar's38 backwardly so that the bars 43 push the stirring barstoward the rear of the body. While the concrete is being hauled in thetruck the stirring bars are constantly reciprocatedfrom one end of-thetruck body to the other in the manner described.

' The hydraulic apparatus for operating the cylinder 23 is notillustratedin'detail since such systems are well known. Valve 55 ispreferably a solenoid-type valve whose action is controlled by the limitswitches 56 shown in Fig. 6.- Preferably these switches are positionedsothat their followers 58 and 59 roll on the peripheral surface of the hub58. of crank 36. 1 The. studs 60 and 6| are embedded in the surface ofhub 58 in the path of the followers. As .the crank 30 isswung to itsmost forward position, stud 60 moves into contact with the follower' 58whichcloses its switch 56. This energizes the solenoid valve-55 whichthen operates to cut off the fluid flowing against one side of thepiston inside the cylinder 23 and permits the liquid to flow into thecylinder against the opposite side of the piston thereby swinging thecrank backward. At the rearmost position of the crank, stud Bl contactsthe follower 59 so that the solenoid is again energized and the movementof the piston rod is reversed. Each Qfth pl tes '5 is p ovided .w h s vThe movement of rod 29 swings holes such as holes 63 and til-between thehole 49 andthe rollers I 8. The pin 48 may be-re moved from hole 49 andinserted into; one of see he z 119165 q t a tnelena of the bar 43 m aybe; fastened at anyone of several different positions on plate .-l-to-vary the point from v which: the stirring element. is pulled.Ordinarily the end of the bar 43;,is connected to pull at;about thecenterof theiload of concrete -t t. the is n te denc tt t h i e o wa .0ae ward. a it m e ou h the concrete.

Preferably the body will be filled with concrete to a point just abovethe upper stirring bar so that this bar is moved back and forth throughthe concrete just below the surface to prevent a crust from forming onthe surface. If the stirring element is not completely submerged in theconcrete the vertical posts 5 between the bars will prevent a crust fromforming on the surface.

The stirring element is moved back and forth through the load ofconcrete with a slow, regular reciprocating motion. As it moves forwardthe sharp forward edge 1 of each stirring bar plows through theconcrete. The upper tapered surfaces 9 displace particles of aggregate,etc. in the concrete upwardly and prevent their settling to the bottom.0n the backward movement the edges 8 and the tapering surfaces 9 abovethem produce the same effect.

This stirring action is considerably different from the conventionaltumbling agitatingmovement. There is no grinding or pulverizing of theaggregate which tends to strip the paste coating from the aggregate. Theconcrete may be stirred for considerable periods without becomingovermixed. This prevents the segregation of the components of theconcrete and the concrete is maintained at the desired plasticity untilit is ready to be poured into the forms at the construction site.

Concrete mixtures differ from one locality to another depending uponwhether the aggregates are smooth or sharp edged, and experts evenrecommend different mixtures using the same aggregate. Applicant istherefore not to be limited to any particular mixture, but suggests asillustrative a 1-2-4 mixture, meaning a mixture in which the weights ofPortland cement, sand and aggregate are used in the ratio of 1:2:4. Thewater used will vary depending upon various factors, including theamount of moisture in the sand and aggregate. One may use, for instance,about 24 gallons of water, more or less, per yard of dry mixture.

After thorough mixing in a standard mixer, the composition istransferred to a truck equipped with a. stirring element of the typeillustrated in the drawings. The inside dimensions of the body I!) ofthe truck are about 6%; feet wide by 10 feet long and 24 to 30 incheshigh. This will hold about four. to five yards of the mixture. Thebottom bar is about 1% inches above the bottom of the body of the truck,but this distance may be varied, and is preferably only slightly fartherfrom the bottom of the truck than the greatest distance through theaggregate. The stirring element is moved back and forth at the rate ofone complete cycle in about two minutes. This speed is preferablyvariable so that it can be increased for longer and heavier hauls. Thestirring element may be designed so that the lower bar is adjustable toa position close to the bottom of the body or to a position furtherabove the bottom to accommodate different sizes of aggregate. The barsabove the bottom bar may also be designed to be tilted forwardly andbackwardly. A suitable water tank may also be provided with thisequipment. The tank maybe installed on the truck at a convenientlocation so that" water may be added to a mixture from time to time asit may be required. This supply of water is also useful for rinsing outthe body after a load of concrete is emptied.

The concrete mixture can be dumped from the truck at the constructionsite by raising one end of the truck body. The amount of water shouldnot be so great as to give a slump of more than two inches when the mixis dumped at the construction site. A slump of one to one and one-halfinches is preferred, Slump is measured according to A. S. T. M.designation C 143-39.

The preferred equipment is simple, easily fabricated, and is easilyinstalled on the body of a conventional truck or dump truck. It may alsobe installed on railroad gondola cars and other vehicles. The parts areeasily replaceable and no precision work is required. The equipment isconsiderably more economical than the very expensive rotary agitatorsfor which special trucks are built. A further advantage in thisequipment is that it does not limit the use of the truck on which it isinstalled to the sole purpose of hauling concrete because when theagitating element is in its forward position against the front of thebody the truck may be used to haul dirt, tile, etc.

The term Portland cement is used herein to include fast-settingmodifications of the original type of Portland cement.

The apparatus is not limited to the particular design disclosed. Theinvention is defined in the claims.

What I claim is:

1. In combination with a truck body capable of containing liquidconcrete, a track fastened along each side of the body, rollers to rollon said tracks, upright members supported by the rollers and located inthe body and close to the two sides thereof, and stirring means which issupported by the uprights and extends substantially from one side of thebody to the other and close to the bottom of the body from one sidethereof to the other as well as a substantial distance above the bottom;and driving means for reciprocating the rollers, upright members andstirring means from one end of the tracks to the other.

2. The combination of claim 1 which includes downward extensions outsideof the truck body from the respective upright members, drive meansconnecting the same to a shaft located below the body of the truck, afluid pressure cylinder and drive means connecting the cylinder with theshaft for turning the shaft first in one direction and then in the otheras the plunger of the cylinder moves in and out thereof, thereby movingthe stirring means back and forth in the truck body by means of saidfirst-mentioned drive means.

3. In combination with an open rectangular truck body capable ofcontaining liquid concrete, a track fastened along each side of theoutside of the body and extending substantially from one end thereof tothe other, rollers supported on the respective tracks, upright membersin the truck body and located close to the sides thereof, said uprightmembers being supported spasms 7.: from the rollers, a plurality ofnarrow stirring bars disposed horizontally inside the body and spacedone above the other, with the top bar considerably below the top edge ofthe truck body and the bottom bar close to the bottom of the inside ofthe body, said bars being fastened to the uprights, power means formoving the rollers, uprights and bars back and forth along the tracks,and driving means connecting the same with the power means. 7

' ERNESTO D. ALESSIO.

REFERENCES CITED The following references are of record in the file ofthis patent:

Number STATES PATENTS Name Date Prochnow Mar. 18, 1884 Garvey Oct. 21,1890 Has'sam Feb. '9, 1909 Lockwood Sept; 6, I932 Shorter Jan. 17, 1933Morrow Feb. 21, 1933 Coulboum Sept. 18; 1934 Feltault Nov. 12, 1935Sinks Dec. 17, 1935

